Audio to Text (Rust)

Rust port of the Python audio_to_text example.

Walks local audio files, transcribes each with OpenAI Whisper, and stores one row per file in Postgres — keyed by filename, so the table is an index of available transcriptions.

Parallel to the Python example

Concern	Python	Rust (this example)
Source	`localfs.walk_dir`	`cocoindex::fs::walk`
Per-file compute	`@coco.fn(memo=True) process_file`	`#[cocoindex::function(memo)] transcribe`
Transcription	`LiteLLMTranscriber("whisper-1")`	OpenAI `/v1/audio/transcriptions` (`whisper-1`)
Target	`postgres.mount_table_target`	`postgres::mount_table_target`

Incrementality: unchanged audio files are memo-skipped; rows for removed files are reconciled away (the managed TableTarget deletes orphaned rows).

Target table is coco_examples.audio_transcriptions with filename (primary key) and text.

Run

bash

export POSTGRES_URL=postgres://cocoindex:cocoindex@localhost/cocoindex
export OPENAI_API_KEY=...

cargo run                     # walk ./audio_files -> transcribe -> Postgres
cargo run -- /path/to/audio   # custom source directory